As regards semiconductor wafers, flattening a surface of a wafer has been conventionally demanded in order to create a fine pattern based on a photomechanical process. In particular, surface waviness that is called “nanotopography” is waviness having a component of a wavelength λ=0.2 to 20 mm and a PV value (a Peak to Valley value) of 0.1 to 0.2 μm or less, and a technology for improving flatness of a semiconductor wafer by reducing this nanotopography has been suggested in recent years. As such a flattening machining method for a wafer, there has been disclosed a machining process including a resin applying step of covering an entire first surface of a wafer sliced out from an ingot and a step of holding the first surface of the wafer, grinding a second surface of the wafer, then holding the second surface of the wafer, and grinding the first surface of the wafer (e.g., Patent Document 1). Further, there has been disclosed a machining process including a primary grinding step of holding a first surface of a wafer sliced out from an ingot, grinding a second surface of the wafer, then holding the second surface of the wafer, and grinding the first surface of the wafer, a resin applying step of covering the entire second surface of the wafer with a resin after the primary grinding step, and a step of holding the second surface of the wafer as a reference surface after the resin applying step, grinding the first surface of the wafer, removing the resin, and then determining the first surface of the wafer as a reference surface, and grinding the second surface of the wafer (e.g., Patent Document 2). Furthermore, there has been disclosed a machining process including a lapping step or a double-disk grinding step of uniforming a thickness of a wafer sliced out from an ingot by lapping or double-disk grinding and removing waviness of the wafer generated by slicing, and a grinding step of performing surface grinding with respect to surfaces of the wafer in accordance with each surface or at the same time (e.g., Patent Document 3).
On the other hand, as a method for slicing a single-crystal ingot, a method for performing slicing by a fixed abrasive grain type wire saw having abrasive grains fixed on a wire outer peripheral surface is to be used in place of a loose abrasive grain type for supplying a cutting fluid containing abrasive grains to a wire saw in order to assuredly supply the abrasive grains to a position near the center of a growth axis of a crystalline ingot (e.g., Patent Document 4).